title: First demonstration of leukemia imaging with the proliferation marker 18F-fluorodeoxythymidine.
abstract: Acute myeloid leukemia (AML) is a neoplasm of hematopoietic stem cells with partial or complete loss of the ability to differentiate but with preserved proliferation capacity. The aim of our study was to evaluate if the in vivo proliferation marker 3'-deoxy-3'-18F-fluorothymidine (FLT) is suitable for visualizing leukemia manifestation sites and if 18F-FLT is a surrogate marker for disease activity.
  
  
  METHODS
  In this pilot study, 10 patients with AML underwent pretherapeutic imaging with 18F-FLT PET or 18F-FLT PET/CT. The biodistribution of 18F-FLT was assessed 60 min after intravenous injection of the radiotracer. Standardized uptake values were calculated for reference segments of bone marrow, spleen, and normal organs. 18F-FLT PET in 10 patients with benign pulmonary nodules and the absence of malignant or inflammatory disease served as controls.
  
  
  RESULTS
  Retention of 18F-FLT was observed predominantly in bone marrow and spleen and was significantly higher in AML patients than in controls (mean 18F-FLT SUV in bone marrow, 11.5 and 6.6, P < 0.05; mean 18F-FLT SUV in spleen, 6.1 and 1.8, P < 0.05). Outside bone marrow, focal 18F-FLT uptake showed extramedullary manifestation sites of leukemia in 4 patients (meningeal disease, pericardial, abdominal, testicular, and lymph node), proven by other diagnostic procedures.
  
  
  CONCLUSIONS
  This pilot study indicated that PET using 18F-FLT is able to visualize extramedullary manifestation sites of AML and reflects disease activity. Because 18F-FLT uptake in bone marrow is caused by a combination of both neoplastic and normal hematopoietic cells, the correlation of 18F-FLT uptake in bone marrow and leukemic blast infiltration did not reach statistical significance.
authors.affiliation: Department of Nuclear Medicine, University of Ulm, Ulm, Germany. andreas.buck@tum.de
authors.forename: Andreas K
authors.initials: AK
authors.lastname: Buck
authors.forename: Martin
authors.initials: M
authors.lastname: Bommer
authors.forename: Malik E
authors.initials: ME
authors.lastname: Juweid
authors.forename: Gerhard
authors.initials: G
authors.lastname: Glatting
authors.forename: Stephan
authors.initials: S
authors.lastname: Stilgenbauer
authors.forename: Felix M
authors.initials: FM
authors.lastname: Mottaghy
authors.forename: Melanie
authors.initials: M
authors.lastname: Schulz
authors.forename: Thomas
authors.initials: T
authors.lastname: Kull
authors.forename: Donald
authors.initials: D
authors.lastname: Bunjes
authors.forename: Peter
authors.initials: P
authors.lastname: Möller
authors.forename: Hartmut
authors.initials: H
authors.lastname: Döhner
authors.forename: Sven N
authors.initials: SN
authors.lastname: Reske
mesh_terms: D000328:Adult; D000368:Aged; D001853:Bone Marrow / Q000378:metabolism; D016022:Case-Control Studies; D049109:Cell Proliferation; D015224:Dideoxynucleosides / Q000378:metabolism / Q000493:pharmacokinetics; D005260:Female; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D014018:Tissue Distribution; D055815:Young Adult
chemical_list: D015224:Dideoxynucleosides; C002854:alovudine